Pump plunger



Sept. 29, 1931.

FIG.

F. E. SPRAGUE PUMP PLUNGER Filed Aug. 6, 1950 Flo-.2.

I R3 i r7 i l8 g 1 32 J I i} 6 p ll I INVENTOR F.E.SPRAGUE ATTORNEYS Patented Sept. 29, 1931 UNITED STATES rum? ILUNGER Application filed August 6, 1930. Serial Ito. 473,356.

This invention relates to pumping machinery, and more especially to animproved type of pump plunger.

An object of the invention is to provide a i .5 novel and unusually eificienttype ofpacker for use upon the reciprocating plunger of a fluid pump, this packer being designed especially for use in pumping oil wells, although it is not necessarily limited to such use. The packer of the present invention, is designed to take the place of the conventional cup leather.

The invention possesses other objects and advantageous features, some of which,'with those enumerated, will be set forth in the following description of the inventions particular embodiment which is'illustrated in the drawings accompanying and forming a part of the specification.

Referring to the drawings:

Figure 1 is a view in side elevation, of a conventional pump barrel, the upper end of which is broken away and shown in section to reveal a pump plunger operatively associated therewith. y

Fig. 2 is an enlarged view partially in vertical section and partially in side elevation, of the pump plunger.

One of the difficulties frequently encountered in connection with pumping, oil and other fluids by means of a reciprocable pump plunger. having thereon one or more cup leathers, results from the fact that the material of which the cup leathers are constructed, is relatively soft, and accordingly, is subject torelatively rapid wear. Particularly true is this when sand is held in suspension in the fluid being pumped, inasmuch as the particles of sand operate as a highly efiicient abrasive which cuts rapidly into the cup leather, inasmuch as the cup leather is of softer material than the pump barrel against which the leather slides during reciprocation of the plunger. The device of the present invention has been produced for the purpose of materially lengthening the period during which a pump plunger may operate without requiring replacement of its cup leathers. This has been accomplished by substituting for the conventional cup leather, a metallicpacking member to be carried by the plunger in-slidi'ngfengagement with the bore of the pump plunger. This packer is provided with means for at taching it in operative position to the core of the plunger, and with a skirt so constructed that it is possessed of suflicient resilience to permit expansion thereof into sealing engagement with the bore of, the barrel,fthi-s expansion being effected by the pressure of the column of fluid being raised, acting against the inside surface of the skirt. 1 j,

Fig. 1 shows a plurality of these sliding packers 6 rigidly mounted upon; a pump plunger 7 which is adapted to bereciprocated within a conventional pump barrel 8, through 'the expedient of a pump rod 9, in the wellknown manner. Preferably the plunger 7 is also of conventional design, and comprises a tubular core 11 having a bore 12 therethrough. This core 11 is preferably releasably attached to the bottom of a valve seat 13 withrwhich a ball valve 14 is associated, this ball valve .14 being restrained by a cage 16 at the top of which a threaded pin 17 is providedto per: mit coupling thereof, to the pump rod 9.. ,At the upper end of the core 11 a shoulder 18- is formed, whereas at the lower end, threads19 are providedfor the reception of a nut21, the shank 22 of the core 11 between the nut 21 and the shoulder 18, being of suflicient. length to accommodate preferably a plurality of sleeves 23. v

The bore of each sleeve 23is of sufficient diameter to permit the sleeve to be placed upon the shank 22 of the core 11. An annular shoulder 24 is formed at therupper endof each sleeve 23, and an annular shoulder 26 of less diameter than the shoulder .24, is formed at the lower end of each sleeve- Each of the packers 6 comprises a head '27 having an aperture 28 therethrough, the di ameter of which preferably coincides to the diameter of the bore of each ofthe sleeves 23, so thatthe aperture 28 is adapted to embrace the shank 22 of the core 11. The remainder PATENT oF Ic of each packer 6 comprises a cylindrical skirt employed should be resistive against-wear due to friction, and relatively inert against the action of water and the chemicals fre quently found in crude oil as pumped from the well.

The flexibility and resilience of the skirt 29 of each of the packers 6, is enhanced by slitting it spirally as indicated at 31, thus defining preferably a plurality of spiral strips 32, all of which cooperate to define the cylindrical skirt 29. Preferably each slit 31 is quite narrow, so that the strips 32 are closely adjacent each other along their lateral edges. Owing to the fact that the strips 32 are of spiral configuration, they are materially longer than would be the case if the slits 31 were formed in the skirt parallel to the axis of the packer, with the result that each of the strips 32 may be bent outwards into frictional engagement with thebore 33 of the pump barrel 8, much more easily. In fact, in the preferred construction of the packer, each of the spiral strips 32 extends throughout substantially the entire circumference of the skirt 29. Moreover, each plate 31 is deflected toward the next slit adjacent the head 27, thereby decreasing the width of the strip 32 defined by these slits, at the line of intersection of the strip with the head. This serves to further increase the flexibility of the strips.

The packers 6 are mounted upon the shank 22 of the core 11 by first slipping a sleeve 23 onto the shank, until its shoulder 24 comes into engagement with the shoulder 18. One of the packers 6 is then inserted with its skirt QQ-extending toward the shoulder 18' from the head 27 of the skirt. The packer is slid upwards on the shank 22 until the head 27 engages the lower end of the sleeve 23, thus positioning the skirt 29 about the associated sleeve. The skirt 29 of each of the packers Sis shorter than the portion of the associated sleeve 23- which is disposed between the shoulders 24 and 26, with the result that an annular space 36 is left between the upper edge of the skirt 29' and the shoulder 24:. Moreover, the outside diameter of the sleeve between the shoulders 24c and 26 thereof, is slightly less than the inside diameter of the skirt, thus leavingan annular space 37 with which the space 36' communicates to permit entrance of fluid to the interior of the skirt. The outside diameter of the annular shoulder 26 of eachsleeve 23, is equal to, or only slight- 1y less'than the insidediameter of the skirt 29 of the associated packer, with the result that this shoulder 26 serves to hold the packer co axially with respect to the sleeve 23- and the shank 22" of the core 11 Another sleeve 23- is then placed upon the shank 22 and slid upwards thereon until the shoulder 24 of the sleeve engages the under side of the head 27 of the packer 6' already placed upon the core. Then another packer 6" is placed" in position, and so on until the total number of sleeves and packers to be tween the lower end of the associated sleeve 7 and the nut 21. Preferably each alternate packer 6 is formed with its strips describing spirals, the pitch of which is opposite to that of the strips 32 of the intermediate packers 6. This is illustrated upon Fig. 1, which shows the strips 32 of the uppern'iost packer to be of right-hand pitch, while the strips of the packer immediately therebclow are of left-hand pitch, and so on. If the strips 32 of all the packers 6 were of common pitch, a small quantity of fluid might leak past one of the packers in spiral streams through the slits 31, and, continuing in spiral flow, enter the slits 31 of the next lower packer; but, by making the slits of opposite pitch, possibil ty of leakage in this manner, is prevented.

In this manner, all the packers will be rig idly mounted upon the shank of the core 11 with the skirt 29 of each packer extending upwards from the head 27 thereof. irCCUlTl ingly, when the plunger 7 is raised within the pump barrel 8 by means of the pump rod 0, fluid will enter the annular space 37 and press the strips 32 of each of the skirts 29 outwards into sealing engagement with the bore 33 of the barrel 8, it being understood that the parts are so proportioned that the diameter of each packer 6 is only slightly less than the inside diameter of the barrel 3. A ccordingly, on the upstroke of the plunger 7, the column of fluid will be raised within the pump barrel. Upon the downstroke of the plunger, the ball 14 will be lifted from its seat. permitting the plunger 7 to move downwards with the fluid passing upwards within the plunger through the bore 12 thereof, it being under rtood that suitable check valves are employed to preventreturn of the column of fluid.

By providing the sliding packer composed of metal instead of the conventional leather or equivalent material, it is found that the length of time that a plunger may be employed without replacing its packers. is ma terially increased because packers o constructed are less subject to being worn out as a result of their frictional engagcn'ient with the bore of the pump barrel.

It is to be understood that the details of the invention as herein disclosed, are subject to alteration within the spirit or scope of the appended claims.

I claim 1. In a pump plunger, a core adapted to be reciprocated within a pump barrel, and a sliding packer carried by said core in sliding ill;

engagement with said barrel and comprising a cup-shaped member of substantially resilient metal having a relatively thin cylindrical side wall divided into spiral strips, each of said spiral strips extending substantially throughout the complete circumference of said packer.

2. In a pump plunger, a core adapted to be reciprocated within a pump barrel, and a sliding packer carried by said core in sliding engagement with said barrel and comprising a head engageable with said core and a plurality of spiral strips of substantially resili ent metal extending from said head, said strips being closely adjacent each other at their lateral edges and cooperating with each other to define a cylindrical skirt, and each of said spiral strips extending substantially throughout the complete circumference of said packer.

3. In a pump plunger, a core adapted to be reciprocated within a pump barrel, and a sliding packer carried by said core in sliding engagement with said barrel and comprising a head engageable with said core and a plurality of spiral strips of substantially resilient metal extendingupward from said head, said strips cooperating with each other to define a cylindrical skirt, each of said spiral strips extending substantiallythroughout the complete circumference of said packer and the upper edges of said strips being spaced from said core to permit entrance of fluid to the interior of said skirt.

i. A pump plunger comprising a core adapted to be reciprocated within a pump barrel, and a plurality of sliding packers carried by said core in sliding engagement with said barrel, each packer comprising a cupshaped member of substantially resilient metal having a relatively thin cylindrical side wall divided into spiral strips, the strips of each alternate packer being of opposite pitch with respect to the strips of the intermediate packers.

5. A packer for a pump plunger, comprising a head having an aperture therethrough adapted to receive the core of said plunger, and a cylindrical skirt of substantially resilient metal divided by spiral slits into a plurality of spiral strips, each of said strips extending throughout substantially the complete circumference of said packer.

6. A packer for a pump plunger, comprising a head having an aperture therethrough adapted to receive the core of said plunger, and a cylindrical skirt of substantially resilient metal divided by spiral slits into a plurality of spiral strips, each of said strips extending throughout more than half the circumference of said packer.

7 A packer for a pump plunger, comprising a head having an aperture therethrough adapted to receive the core of said plunger, and a cylindrical skirt of substantially resilient metal divided by spiral slits into a plurality of spiral strips, each of said strips extending throughout more than half the circumference of said packer, and each of said slits being deflected toward the slit at one side thereof adjacent said head to increase the fiexibility'of the strip therebetween.

In testimony whereof I have signed my name to this specification.

FRANK E. SPR-AGUE. 

